Effect of neonatal exposure to diethylstilbestrol and tamoxifen on pelvis and femur in male mice

✍ Scribed by Fukazawa, Yugo ;Nobata, Sigenori ;Katoh, Miho ;Tanaka, Masami ;Kobayashi, Sinji ;Ohta, Yasuhiko ;Hayashi, Yokichi ;Iguchi, Taisen

• Publisher: John Wiley and Sons
• Year: 1996
• Tongue: English
• Weight: 894 KB
• Volume: 244
• Category: Article
• ISSN: 0003-276X
• DOI: 10.1002/(sici)1097-0185(199603)244:3<416::aid-ar12>3.0.co;2-s

✦ Synopsis

Background: Permanent abnormalities have been reported in reproductive and non-reproductive organs of mice and humans exposed perinatally to a synthetic estrogen, diethylstilbestrol (DES). Recent studies demonstrated that sex hormones affected the shape of the innominate bone in mice. Therefore, we analyzed the long-term effects of neonatal exposure of DES and tamoxifen, an anti-estrogen, in mouse bones.

Methods: Changes in the pelvis and femur were examined in 1-to 15month-old C57BL/Tw male mice given 5 daily injections of 3 pg DES or of 100 pg tamoxifen beginning on the day of birth by measuring contents of calcium (Ca) and phosphorus (P), and the numbers of osteoblasts and os- teoclasts.

Results: The ash weight of pelvis and femur in neonatally DES-and tamoxifen-treated mice was lower than that in the controls at %15 months of age. Contents of Ca and P of pelvis and femur in neonatally tamoxifentreated mice were lower than in the controls and neonatally DES-treated mice. In neonatally DES-treated mice at 6-12 months, Ca and P contents in the pelvis were lower than in controls, but not different in the femur. The number of osteoblasts per unit length of endocortical surface of the femur in 2-and 3-month-old DES-and tamoxifen-treated mice was lower than that in the controls. The osteoclast number in the femur in DES-treated mice at 2 to 12 months was not different from that in the controls; however, in tamoxifen-treated mice, the number was higher than in the controls. An epiphyseal line was clearly detected in the femur of 12-and 15-month-old DES-and tamoxifen-treated male mice, whereas the line in the controls disappeared after 12 months.

Conclusions: The present results indicate that in male mice, neonatal exposure to DES and tamoxifen induced permanent changes in the pelvis and the femur, and that tamoxifen had a greater effect on bone tissue than did DES.